Internal combustion engine



y 1938. H. L. BURk H ARDT 2,117,700

I INTERNAL COMBUSTION ENGINE Filed June 28, 1955 2 Sheets-Sheet 1 INVENTOR. c -G- 4 BY Haney L. fiwamneor 3 M ATTORNEY5.

y 7, 1938. H. L. BURKHARDTV 2,117,700

INTERNAL COMBUST ION ENGINE Filed June 28, 1955 I 2 Sheets-Sheet 2 1N VENTOR.

F76 5 fi flE/FY A Even/near ATTORNEYS Iii Patented May 17, 1938 UNITED STATES PATENT OFFICE 4 Claims.

This invention relates to mechanism for converting reciprocating motion to rotary motion, or vice versa, and is especially applicable to internal combustion engines for motor cars, airplanes, boats, and other purposes, but is also applicable to apparatus such as air compressors, pumps, and rock crushers.

The principal objects of the invention are to provide a mechanism in which the moving parts are in perfect dynamic balance and which will minimize the forces transmitted to the housing structure of the mechanism.

A further object is to provide a compact arrangement of the parts with the consequent saving of space, weight, and reduction in cost of manufacture.

Ihe principal application of the invention is to internal combustion engines and I have chosen such engines for the purpose of disclosing herein illustrative embodiments of my invention.

In the accompanying drawings,

Fig. 1 is a longitudinal section through the cylinders of an internal combustion engine operating on the two-stroke cycle principle, the section being on the line l| of Fig. 2;

Fig. 2 is a longitudinal section on the line 2-2 of Fig. 1;

Fig. 3 is an enlarged section through the motive fluid compressor, the section being on the line 33 of Fig. 2;

Fig. 4 is a detail elevation of the gears connecting the two crank-shafts of the engine;

Fig. 5 is an elevation at the end of one pair of cylinders showing the arrangement of the gas transfer connection between the cylinders;

Fig. 6 is a view similar to Fig. 1 but showing an engine operating on the four-stroke cycle principle;

Fig. 7 is a longitudinal section thereof on the line l--1 of Fig. 6;

Fig. 8 is an end elevation of one of the pairs of cylinders and showing the arrangement of the valve actuating mechanism; and

Fig. 9 is a detail section on the line 99 of Fig. 7, showing the arrangement of the timing gears for operating the cam shafts.

It will be noted from the drawings that the parts of the mechanisms are units that are in common use and the physical characteristics of which are well understood. The illustrative embodiments are complete units, each comprising four cylinders, but it will be understood that these units may be duplicated to provide engines having eight or twelve cylinders or any other multiple of four cylinders, all having two crank-.

the axis of the cylinder I 5.

shafts in common. Briefly, the illustrative embodiments of my invention each comprises two pairs of opposed cylinders and each cylinder being provided with its piston and connecting rod, the axes of the cylinders being arranged substantially in the same plane and each cylinder being directly opposite one of the cylinders of the other pair. Twocrank-shafts, each havin a single crank pin, are disposed between the pairs of cylinders with their axes normal to the plane of the cylinder axes. Two connecting rods connect each crank pin with the pistons of opposed cylinders, and the crank-shafts are geared together to rotate at equal angular velocities but in opposite directions. The crank pins are angularly positioned, relative to each other, to cause the reciprocating parts to move in the same direction at all times, and balancing weights of proper mass are disposed opposite each crank pin.

Referring to Figs. 1 to 5, it will be noted-that there is a crank casing l0 having two pairs of bearings II for the crank-shafts I2 and i3. Secured to one side of the crank case I0 is a block comprising the cylinders l4 and I5 which may be suitably water-jacketed in accordance with well-known practice. The cylinder 14 has an annular. inlet port I6 surrounding its inner wall and said wall is provided with a circumferential series of radial ports I! whereby the port I6 communicates with the interior of the cylinder in which the piston I8 reciprocates. A motive fluid supply pipe l9 connects with the port l6 and with the discharge orifice of the com pressor 2|.

The cylinder I 5 has an annular exhaust port 22, surrounding its inner wall, and a circumfer-' ential series of radial ports 23 extending therefrom to the interior of the cylinder in which the piston 24 reciprocates. An exhaust pipe or manifold 25 is connected to the port 22.

The piston I8 is connected with the crank 26, of the crank-shaft 12, by a connecting rod 21, and the piston 24 is connected with the crank 28, of the crank-shaft I3, by a connecting rod 29.

On the opposite side of the crank case Ill, from the block containing the cylinders l4 and I5, there is a similar block containing the cylinders and 3!, the axis of the cylinder 30 being in alignment-with the axis of the cylinder [4 and the axis of the cylinder 3| being in alignment with The cylinder 30 is provided with an annular inlet port 32, similar to the port 18, and the cylinder 3| is provided with an annular exhaust port 33, similar to the port 22, and in other respects the cylinders 30 and 3| are similar to the cylinders I4 and I5. The inlet port 32 has a branch of the motive fluid supply pipe I9 connected therewith and the ex-. haust port 33 has a branch of the exhaust pipe or manifold 25 connected therewith.

There is a piston 34 in the cylinder 38 and a piston 35 in the cylinder 3| and the piston 34 is connected with the crank 26 by the connecting rod 36 and the piston 35 is connected with the crank 28 by the connecting rod 31. The cylinders I 4 and I5 are provided with a removable head block 38 having a port 39 therein for transferring the gases from the cylinder I4 to the cylinder I5, and it will be noted, from Fig. 5, that the transfer passage 39 communicates with the cylinder I4 at one side and with the cylinder I5, at the opposite side, so that the gases will form and maintain the vortex or swirling motion in passing from one cylinder tothe other. The usual spark plug is indicated at 40. In a similar manner the cylinders 30 and 3| are provided with a head block 4| having a transfer port 42 therein and a spark plug 43.

The compressor 2| is shown in detail in Fig. 3 and comprises a housing 44 having the rotating impellers 45 and 46, constructed according to the Well-known Roots blower principle. The impeller 45 is mounted directly on the crank-shaft I2 and the impeller 46 is mounted on the crankshaft |3 so that these impellers are driven in unison at the crank-shaft speed. The compressor is provided with an in-take pipe 41 which is supplied With the motive fluid by means of the usual carburetor 48. Mounted on the crank-shaft I2 in balancing relation to the crank 26 and the parts connected therewith, are counterweights 49 which are suitably proportioned to provide a perfect dynamic balance. In a similar manner,

' the crank-shaft I3 is provided with the counter- Weights 50. Gears 5| are secured to the crank shafts I2 and 3 and, being of the same diameter and in mesh, cause the crank-shafts to rotate at all times at the same angular velocities.

In the operation of the engine above described, assuming that the pistons I8 and 24 are moving to the right on the explosion stroke, the pistons 34 and 35 will be compressing a charge in the cylinders 38 and 3|. When the pistons I8 and 24 uncover the ports I1 and 23, the burnt gases will be exhausted through the ports 23 and a fresh charge will enter through the ports I! and fill the cylinder I4 and pass through the transfer passage 39 into the cylinder I5 and, because of their swirling motion, will effectively scavenge the burnt gases from both cylinders. At the end of the stroke of the pistons tl'E charge in the cylinders 30 and 3| will be ignited by the spark plug 43 and the pistons will then move in the opposite direction, the ports I! and 23 being thereby closed by the pistons I8 and 24 and the charge being compressed in the cylinders I4 and I5. Toward the end of this stroke of the pistons, the inlet ports in the cylinder 30 and the exhaust ports in the cylinder 3| will be uncovered by the pistons 34 and 35, thereby permitting the burnt gases to be exhausted from the cylinders 38 and 3| and a fresh charge supplied thereto. The pistons will then start on their stroke in the opposite direction and the operations will be repeated so that two of the pistons will start on their power stroke every of revolution of the crankshafts.

In the engine illustrated in Figs. 6 to 9, the crank case, cylinders, pistons, connecting rods and crank-shafts are substantially the same as .rciifllan William in the two-cycle engine above described, but this engine operates on the four-stroke cycle principle and, therefore, each of the cylinders is provided with an inlet valve 6|] and 'an exhaust valve 6| and the head blocks 62 separate the interiors of each pair of cylinders. The crank-shafts are also geared together for rotation in unison and at equal angular velocities at all times. The usual cam shafts 63 and 64 are provided and these cam shafts actuate push rods 65 which are operatively connected with the rocker arms 66 which are suitably mounted on the head blocks 62 and operatively connected with the stems of the valves 68 and 6|, according to common practice.

On the crank-shaft 61 there is a timing gear 68 which meshes with the gears 69 and III on the cam shafts 63 and 64, respectively, these timing gears being so proportioned that the cam shafts rotate at one-half the speed of the crank-shafts, according to the common practice in four stroke cycle engines.

It is believed that the operation of the engine disclosed in Figs. 6 to 9 will be readily understood from the foregoing description and the drawings and, therefore, a detailed description of the operation will be omitted. Since the unit comprises four cylinders, there will be an explosion stroke in one of the cylinders during each half revolution of the crank-shafts and, by providing each of the crank-shafts with suitably proportioned counterweights for the cranks and masses attached thereto, it will be apparent that the engine will operate in perfect dynamic balance.

Having thus described my invention, I claim:

1. An internal combustion engine comprising two parallel crank-shafts geared together for rotation in opposite directions at equal angular velocities, four cylinders with their axes in parallel relation, said cylinders being arranged in pairs on opposite sides of the common plane of the axes of said crank-shafts, pistons in said cylinders, connecting rods operatively connecting the pistons of two of said cylinders with a crank on one of said crank-shafts, connecting rods operatively connecting the pistons of the other two cylinders with a crank on the other crank-shaft, the relation of said cranks being such that all of said pistons move, at all times, in unison and in the same direction, and means for controlling the motive fluid supply and exhaust for the different cylinders.

2. An internal combustion engine comprising two parallel crank-shafts geared together for rotation in opposite directions at equal angular velocities, four cylinders with their axes in parallel relation and in a common plane, the axes of two of said cylinders being in a plane which includes the axis of one of said crankshafts, the axes of the other two cylinders being in a plane which includes the axis of the other of said crank-shafts, pistons in said cylinders, connecting rods operatively connecting the pistons in the first mentioned two cylinders with a crank on one of said crank-shafts, connecting rods operatively connecting the pistons in the other two cylinders with a crank on the other crank-shaft, the relation of said cranks being such that all of said pistons move, at all times, in unison and in the same direction, and means for controlling the motive fluid supply and exhaust for the different cylinders.

3. An internal combustion engine comprising two parallel crank-shafts geared together for rotation in opposite directions at equal angular iii aim-mo velocities, four cylinders with their axes in parallel relation, said cylinders being arranged in pairs on opposite sides of the common plane of the axes of said crank-shafts, pistons in said cylinders, connecting rods operatively connecting the pistons of two of said cylinders with the same crank on one of said crank-shafts, connecting rods operatively connecting the pistons of the other two cylinders with the same crank on the other crankshaft, counterweights on each of said crank-shafts for balancing said cranks and the masses attaehedthereto, the relation of said cranks being such that all of said pistons move, at all times, in unison and in the same direction, and means for controlling the motive fluidfsnpply and exhaust for the difierent cylinders.

4. An internal combustion engine comprising" two parallel crank-shafts geared togetherfor rotation in opposite directions at equal angular velocities, four cylinders with their axes in parallel relation and ina common plane, the axes of two of said cylinders being in a. plane which includes the axis of one of said crank-shafts, the axes of the other two cylinders being in a plane which includes the axis of the other of said crank-shafts, pistons in said cylinders, connecting rods operatively connecting the pistons in the first mentioned two cylinders with the same crank on one of said crank-shafts, connecting rods operatively connecting the pistons in the other two cylinders with the same crank on the other crank-shaft, counterweights on each of v said crank-shafts for balancing said cranks and the masses attached thereto, and means for controlling the motive fluid supply and exhaust for the different cylinders.

HARRY L. BURKHARD'EI. 

